Cleaning up the BINARYEN how-to

Cleaning up the BINARYEN how-to
Update Dockerfile to compile successfully

Cleaning up the BINARYEN how-to

Cleaning up the BINARYEN how-to

Cleaning up the BINARYEN how-to

WASM_LLVM_CONFIG will now be a properly cached variable, settable with
cmake -DWASM_LLVM_CONFIG=/path/to/llvm-config and persisting across runs
of cmake and editable with ccmake|cmake-gui.  If the value was not
specified on the command line or retrieved from the cache, it will
resort to the environment variable.

Signed-off-by: NZiyan Zhou <zhouziyan@hotmail.com>

up the minimum required boost level to 1.64 to fix problem with string::data() only returning a const char *

From where I'm standing, #35 is just due to the outdated genesis.json
and docs. Looks fixed to me.